SUMMARYCaveolin is a generic term for a family of proteins that include caveolin-1, -2 and -3. Although the distribution of these proteins varies between cells, caveolin-1 and -2 are commonly found coating membrane invaginations known as caveolae. Studies on human and murine cells suggest that caveolin/caveolae can be found in neutrophils, macrophages and mast cells, in which they are involved in the uptake of pathogens, but not in lymphocyte cell lines. Expression of caveolin-1, -2 and -3 in bovine immune cells was investigated using confocal microscopy and Western blotting. Staining for caveolin-1 was evident in all peripheral blood mononuclear cells (PBMC) and in CD4 + , CD8 + and CD21 + lymphocytes, monocytes, macrophages and monocyte-derived dendritic cells (DC). In addition, the caveolin-1 antibody detected a protein with a molecular weight of approximately 22 000 in all PBMC, macrophages and DC, as well as in bovine aortic endothelial (BAE)-1 cells and human endothelial cells by Western blotting. In macrophages and DC, caveolin co-localized with the endoplasmic reticulum±Golgi intermediate compartment (ERGIC) and to a lesser extent with Golgi, but not with endoplasmic reticulum. Staining was not seen on the plasma membrane in any bovine immune cells, suggesting the absence of caveolae, while in BAE-1 cells staining was predominantly on the cell membrane. Caveolin-2 could not be detected in any bovine cells by confocal microscopy or Western blotting, while caveolin-3 was detected in all bovine cells by Western blotting, but not by confocal microscopy. These data provide evidence for the presence of caveolin in bovine lymphocytes and antigen-presenting cells.

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OBJECTIVE: Deficiencies of vitamin A and iodine are common in many developing countries. Vitamin A deficiency (VAD) may adversely affect thyroid metabolism. The study aim was to investigate the effects of concurrent vitamin A and iodine deficiencies on the thyroid-pituitary axis in rats. DESIGN: Weanling rats (n = 56) were fed diets deficient in vitamin A (VAD group), iodine (ID group), vitamin A and iodine (VAD + ID group), or sufficient in both vitamin A and iodine (control) for 30 days in a pairfed design. Serum retinol (SR), thyroid hormones (FT(4), TT(4), FT(3), and TT(3)), serum thyrotropin (TSH), pituitary TSHbeta mRNA expression levels, and thyroid weights were determined at the end of the depletion period. MAIN OUTCOME: Compared to the control and ID groups, SR concentrations were about 35% lower in the VAD and VAD + ID groups (p < 0.001), indicating moderate VA deficiency. Comparing the VAD and control groups, there were no significant differences in TSH, TSHbeta mRNA, thyroid weight, or thyroid hormone levels. Compared to the control group, serum TSH, TSHbeta mRNA, and thyroid weight were higher (p < 0.05), and FT4 and TT4 were lower (p < 0.001), in the VAD + ID and ID groups. Compared to the ID group, TSH, TSHbeta mRNA, and thyroid weight were higher (p < 0.01) and FT(4) and TT(4) were lower (p < 0.001) in the VAD + ID group. There were no significant differences in TT3 or FT3 concentrations among groups. CONCLUSION: Moderate VAD alone has no measurable effect on the pituitary-thyroid axis. Concurrent ID and VAD produce more severe primary hypothyroidism than ID alone. Objective: Deficiencies of vitamin A and iodine are common in many developing countries. Vitamin A deficiency (VAD) may adversely affect thyroid metabolism. The study aim was to investigate the effects of concurrent vitamin A and iodine deficiencies on the thyroid-pituitary axis in rats. Design: Weanling rats (n ϭ 56) were fed diets deficient in vitamin A (VAD group), iodine (ID group), vitamin A and iodine (VAD ϩ ID group), or sufficient in both vitamin A and iodine (control) for 30 days in a pair-fed design. Serum retinol (SR), thyroid hormones (FT 4 , TT 4 , FT 3 , and TT 3 ), serum thyrotropin (TSH), pituitary TSH␤ mRNA expression levels, and thyroid weights were determined at the end of the depletion period. Main outcome: Compared to the control and ID groups, SR concentrations were about 35% lower in the VAD and VAD ϩ ID groups (p Ͻ 0.001), indicating moderate VA deficiency. Comparing the VAD and control groups, there were no significant differences in TSH, TSH␤ mRNA, thyroid weight, or thyroid hormone levels. Compared to the control group, serum TSH, TSH␤ mRNA, and thyroid weight were higher (p Ͻ 0.05), and FT 4 and TT 4 were lower (p Ͻ 0.001), in the VAD ϩ ID and ID groups. Compared to the ID group, TSH, TSH␤ mRNA, and thyroid weight were higher (p Ͻ 0.01) and FT 4 and TT 4 were lower (p Ͻ 0.001) in the VAD ϩ ID group. There were no significant differences in TT 3 or FT 3 concentrations among groups. Conclusion: Moder...

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